Exxon Mobil says oil leaked into Yellowstone River

* No information on cause of Montana spill

* Not clear how much released

NEW YORK, July 3 (Reuters) - A pipeline operated by Exxon Mobil Corp (XOM.N) leaked an undetermined amount of oil into the Yellowstone River in Montana, and the pipeline has been shut down, the company said.

In a statement on Saturday, Exxon said it found the leak from the EMPCo pipeline early Saturday morning. The pipeline in question runs only in Montana, from Silver Tip to Billings.

The company said it was still looking into the cause and trying to determine the amount released.

The Billings Gazette on Sunday cited conflicting reports from Exxon officials, with some saying up to 42,000 gallons of crude had escaped.

The leak came one day after a Maryland jury awarded plaintiffs suing Exxon $1.5 billion in damages for a 2006 leak at a gas station. [ID:nN1E7600K1] (Reporting by Ben Berkowitz, editing by Maureen Bavdek)